


The Rate of Inflation

by Superfluous_Gypsy



Series: Kinks Series [1]
Category: The Avengers (Marvel) - All Media Types
Genre: Anal Sex, Comic Book Science, Humor, Kink Exploration, M/M, Mild breeding kink, Verbal Humiliation, Weight Gain, verbal feminization
Language: English
Status: Completed
Published: 2017-03-16
Updated: 2017-03-16
Packaged: 2018-10-05 22:58:52
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,759
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10319210
Author URL: https://archiveofourown.org/users/Superfluous_Gypsy/pseuds/Superfluous_Gypsy
Summary: "I think I can actually feel myself getting fatter! Are these moobs? Please tell me I am not getting moobs." Tony shuddered.Steve squeezed him closer to his super soldier body. "Oh," he groaned, "your ass." Steve started grinding against Tony's plushier rear. "Can I ride your dick?"Tony huffed. "If you can find it and if it's in any condition to be ridden, then knock yourself out, cowboy."An experimental serum reveals that Steve has some really unconventional kinks. Tony caters to them without too much emotional distress. Weight gain, breeding kink, other kinks mentioned.





	

Doctor Bruce Banner was not the type of man who enjoyed being at loose ends. He preferred to keep himself busy.  
With Captain America on call and spending free time around the Avengers' tower, he had plenty of samples of Steve's cells to study how Erskine's serum had affected the human body. Unfortunately, since the specs for the Vita-Ray machine had been destroyed in the '40's, Bruce had hit the cold end of the trail when it came to figuring out what had been in Erskine's serum.

  
But there was nobody better to try to untangle the genetic and phenotypic problems the serum created with Steve Rogers' body.

  
Steve did not have a tendency to complain. On the contrary, Steve preferred to keep any problems or discomfort to himself. But spending so much time among spies and scientists meant that many of the people around him were the type to notice things.

  
Bruce had put his mind to the issue of Steve's hyped-up metabolism. His body expended so much energy during a typical battle that he literally required hours of refueling (i.e. eating) afterward.

  
He believed he had created a possible solution: a liquid mixture of a variety of proteins, acids, phospholipids and pseudolipids, and other compounds that would exponentially increase efficiency of a super soldier's digestive process in a relatively small dose. With chocolate flavoring.  
Unfortunately, Tony Stark was due for a payback prank from Clint Barton.

* * *

"Hey look, Steve actually labeled something," Clint said mildly, waving a stainless steel water bottle. "Does he really expect anyone to respect that?"

  
Tony peered over Clint's shoulder. "That is an intriguing number of exclamation points. Looks like it's written in Sharpie, too."

  
"Dare you to drink it."

  
Tony groaned. "You know the hypocrite will give us that sad face with the big eyes and ask us in that Disappointed Sitcom Dad voice why we couldn't respect his belongings."

  
"You have a disturbing weakness for that Sitcom Dad voice your boyfriend uses. I don't know if that's healthy."

  
Tony turned to Clint with an over-the-top expression of innocence. "Steve was the one who introduced role-play into our-"

  
"Oh my Thor, shut up!" Clint burst out, covering his ears. "I do not want to hear that! Stop trying to make excuses!"

  
Tony gave a razor-sharp smirk and said, "Don't make it out like I'm a wuss, Robbie Stroud," and chugged the whole 14 ounces.

  
The observable effects didn't kick in until nearly two hours later, when the group convened for a massive spaghetti feast.  
Everyone was still in the middle of eating when Tony felt a funny feeling in his stomach. It passed quickly, and he didn't think anything about it until another weird sensation five minutes later that was abrupt and painful enough to make him gasp. He waved everyone's attention away, mumbled an excuse, then left the room.

  
Nothing happened in the bathroom, so he took a tablet and sat on the end of a couch.

  
"Everything okay, Tony?" Steve called.

  
"Fine. Can't eat any more."

  
Tony could hear the rumble of Clint's voice, but was unable to make out the words.

  
_"You idiot!"_

  
That piqued Tony's attention. It wasn't often that Bruce raised his voice. He came out from the dining room and stared at Tony.

  
"What?" Tony asked.

  
"Clint gave you something from my lab!

  
Tony shrugged, feigning nonchalance, but dread began to make his neck itch. "It was a dare. He said it was organic." The rest of the group had entered the living room and were watching.

  
" _Cotton sheets_ can be organic! You don't eat those!" Bruce buried his fingers in his hair.

  
"What did he eat?" Steve asked, looking concerned.

  
Bruce turned to answer him. "That compound I was developing to increase the efficiency of your metabolic process."

  
"So what's it gonna do to him?"

  
Bruce sighed, and spread his arms in frustration. "I don't know for sure. It shouldn't kill you, at least," he said sharply to Tony. "If it has the same effect, he will better digest and retain nutritional elements from anything he eats, and integrate the sugars, lipids, and vitamins into his body, wringing out every useable chemical and putting it to use."

  
"For those of us who didn't waste time taking organic chemistry, translation?" Tony prompted.

  
"Your body should convert the food you eat quickly and efficiently into energy, muscle mass, and even fat deposits."

  
"Whoa, whoa, hang on Professor Farnsworth! Are you saying I'm gonna get fat?!" Tony stood up from the couch with alarm.

  
"Probably, yeah. Though it will serve you right. No one should ever eat or drink anything from a lab! Really, that's the first rule of chemistry, Tony."

  
"Clint had it in the kitchen. In a plain water bottle."

  
"That was labeled 'Steve.' With five exclamation marks."

  
"If you ever find Clint in a lab, he's the test monkey. He doesn't know anything," Natasha said dryly.

  
"Hey, I take offense," Clint said mildly. "But she's probably right."

  
"How could I have known he had taken it from Bruce's lab?" Tony's stomach gurgled loudly, and Tony could feel contents shifting inside. He clutched his abdomen. "Can you reverse it?"

  
"The potential remedy is unfinished," Bruce said. "It hasn't been tested on any living organisms. I wasn't close to even testing on Steve, yet."

  
"What was it, you had, like, five pieces of garlic bread, right? How fat are you gonna get?"

  
"Shut up!" Tony snapped back at Clint. He tucked the tablet under his arm. "I'm going to my room."

  
"Someone should keep an eye on you," Bruce protested.

  
"That's what JARVIS is for," he called back.

  
Tony sprawled on the bed with the tablet. After twenty minutes, he could feel the waistband of his pants cutting into his flesh. "Dammit!" He pulled them off, threw them on the floor, then continued his work, stubbornly avoiding looking at his stomach.

  
Maybe forty minutes after that, his shirt had gotten uncomfortably tight around his chest and biceps. He refused to take off any more clothes. "It can't do that much to me," he muttered.

  
There was a knock on the door only a few minutes later. "Go away!" Tony yelled.

  
"Let me in," Steve said. "JARVIS won't give us any information on your condition."

  
"That's 'cause I told him not to! I'm fine!"

  
"Tony, you said you were fine when you set your sleeve on fire using the toaster last month. You had second degree burns. I don't trust your opinion." Steve was using his serious, 'I know what's best for you, because you paid so much attention to your phone that I had to keep you from falling in an open manhole' voice. Which he had had to do. Twice.

  
Tony rolled his eyes. When he got into Nanny Mode, Steve would not take no for an answer. "Fine. As long as it's just you. Door, JARVIS."

  
Steve stepped in alone, that concerned expression on his face even more intense. "You are not fine. Geez, Tony."

  
"Hey, I can gain a bit of weight and still be fine. Maybe my ass will fill out a bit. Maybe I'll get a cute bubble butt."

  
Steve ignored Tony's jokes. "Have you seen yourself?"

  
"Of course," Tony lied. "Okay, bed check is done, Nurse Ratched. Shoo."

  
Tony's shirt chose that moment to audibly rip at the seams. Before he could stop himself, Tony was looking down at the damage.

  
"Jesus Christ!" It looked like he had gained at least twenty pounds. "Are these moobs? Please tell me I am not getting moobs."

  
Steve was gazing at him intently. "I don't know; what are moobs?"

  
Tony shuddered. "I think I can actually feel myself getting fatter!"

  
"You have a double chin."

  
"Thank you so much, Steve! You can leave now!"

  
Steve walked closer to where Tony lay on the bed. He pulled off a sleeve that had detached from Tony's shirt.

  
"No. You are not allowed to do that. No undressing."

  
"It's not even a shirt anymore."

  
Tony pulled off the remains of the garment. "Fine. There. No more shirt. Laugh, then go away."

  
Steve sat on the bed and put a hand on Tony's cheek. "I am not laughing."

  
Tony could see that Steve wasn't laughing. He looked more transfixed than amused.

  
"Is this turning you on?" Tony asked in disbelief.

  
"Kind of," Steve replied, prodding Tony's newly rounded cheek, then running his fingers down to touch the double chin.

  
"I am so not in the mood," Tony said.

  
"Can I cuddle you, then? Please?"

  
After four months of semi-regular pure-vanilla gay sex, it looked like Steve was actually showing the signs of a kink. Tony really couldn't deny Steve's tentative, hopeful expression.

  
"Fine," he sighed. "But I reserve the right to out you as a chubby chaser."

  
Steve didn't respond. He knee-walked across the mattress and curled up partly over Tony, wrapping one arm around his larger chest and putting the other hand on the new mound of his belly.

  
Tony shuddered again, and Steve's eyes widened. "I could feel that. You got bigger!"

  
Tony let his tablet drop and stared miserably at the ceiling. "I pray to God that this will be easily reversible, and that I won't have to take up Tae-Bo again. I think I only have those videos on cassette tapes. See, Steve? My manic geniousity has kept me in relatively reasonable shape since _the nineties_. I will have to find a damn VCR. JARVIS, do we have a VCR around anywhere?"

  
"You cannibalized it eight years ago to make an automatic sushi roller, sir."

  
"Huh, I remember that. Rice went everywhere."

  
Steve's hand had wandered up and was pinching lightly at Tony's left pectoral. Well, it was way more of a man-boob at this time than a pec.

  
Tony slapped his hand. "Easy. It's tender."

  
Steve's eyes were glazed over. "You have _tits_ , Tony," he sounded awed.

  
Tony leveraged his heavier upper body up into a sitting position. "I would totally take offense to that, but I think I actually got a hard-on hearing you say that word."

  
Steve removed his hands and sat up, too. "Tits?"

  
Tony checked his dick through the fabric of his boxers. The waistband was utilizing much more of its elasticity than it usually needed to. "Yup; at least half the way there."

  
Steve grinned slyly. It wasn't an expression Tony had ever seen on Steve's face before. "Will you let me play with your titties, baby?"

  
This shudder Tony was wracked with was definitely not due to an ingested science experiment. Steve took that as permission to throw a leg over the man, straddle his lap, and use his hands to cup the moobs and squish them up and together. Then he bent his head down and licked the skin.

  
Tony's moan nearly sounded soprano. There was some pounding on the door. "Tony! Steve! Everything okay?!" Clint yelled.

  
"Go away! Sex now!" Tony called back.

  
"Mmm," Steve hummed, enjoying himself by nuzzling into the new titflesh and kneading at Tony's hard cock. "I bet these could fit in a bra. Should I get you a bra? Pink?"

  
Both of them could feel Tony's dick jump. "Whoa. I did not know that was something I'm into." His head was definitely in the game, now. He started feeling up Steve's amazing biceps and shoulders. "Not pink, though. I'm more of a hot rod red kinda girl."

  
Steve pulled away to look at his face. "Your cheeks are all pink. Are you actually feeling _shy?_ "

  
"Shut up." Tony could feel the embarrassment making him blush, but the shame was shockingly erotic.

  
Both of them could feel the next shudder. Tony decided it was time to do away with the boxers and Steve helped pull them off.

  
"You are seriously round," Steve marvelled. "Stand up." Reluctantly, Tony let the man position him so they stood in front of a full length mirror. Steve's body was almost eclipsed by Tony's new rotundity. He was now clearly overweight, bordering on obese. His globular belly hung over his groin, propped up by Steve's wrist as he reached under the flab to stroke Tony's cock. His man-boobs were unnaturally perky, and the flesh of his left one spilled out between the fingers of Steve's broad hand as the blond clutched it with a grip that bordered on discomfort.

  
Tony was a bit relieved that that unfairly ripped bod was behind him and not standing next to him as a contrast, like a real life "Before the Ab-Ass-Erciser" and "After the Ab-Ass-Erciser" commercial.

  
Tony's arms and thighs had also thickened. "I have cankles!" He moaned in distress. Steve started kissing gently up his flabbier neck to soothe him. Tony had a double- no, a triple-chin; and his cheeks were plump and rosy with humiliation.  
"I look like a beardy Kewpie doll," he grouched. "Look at these; I have _thunder thighs!_ " There were actual tears falling down his fat face, now. Tony had had no idea that he had possessed the supernatural ability of being able to cry in despair while maintaining a rampant boner. He idly wondered if that made him less or more of a man.

  
"Bruce will fix this," Steve consoled him.

  
"You don't know that." Tony sniffled.

  
Steve squeezed him closer to his super soldier body. "Oh," he groaned, "your _ass_." Steve started grinding against Tony's plushier rear.

  
At this point Tony was torn between being angry that Steve was ignoring his emotional crisis to take advantage of the horrible effects of his body and being really fucking turned on by how single-mindedly lecherous Captain America had become. He reluctantly ended up on the annoyed side because Steve's denim jeans were frotting against his sensitized skin rather roughly.

  
"If you're going to do that, take your damn pants off! A zipper wedging its way into my crack is not going to improve my situation." Tony turned around to help remove Steve's clothes, then turned his head back to take a look at his butt.

"That is... almost a thing of beauty. Bruce can fix everything else, but I won't slit my wrists if I get stuck with this badonkadonk."

  
Steve had removed his pants and underwear and plastered himself against the front of Tony's body wearing just his shirt and socks. He started mouthing and sucking like a remora. Steve was almost mauling Tony's mouth in his excitement, and his hard cock was trying to bury itself into Tony's overhanging gut, while his hands clutched and kneaded at Tony's moobs.

  
Tony was a bit distracted by the changes to his balance and the pressure on his leg joints. He put a hand over Steve's face and said, "I gotta lie back down." He noticed that the new girth of his thighs made him waddle, and that erotic shame both seemed to heat and chill him at the same time.

  
He fell back onto the bed and wriggled into the middle. "What am I? 300 pounds now? Much closer to Mama Grape than Leo, at this point. This better stop and be reversible, or else they're gonna have to remove my body with a crane."

  
"I don't understand what you're saying," Steve said.

  
"I'm saying that I will kill myself if I keep getting bigger. I can't make an Iron Man suit this big! While the repulsor thrusters have enough oomph to get me off the ground, the wind drag and turning radius will make me about as agile as a blimp. Of which I greatly resemble at the moment."

  
"Okay, keep on complaining if it will make you feel better. I'm gonna get you back in the mood." Tony lost sight of Steve's head as he ducked down behind his belly and began licking his balls.

  
"Steve," Tony said, concerned. "I don't want you to suffocate when this blubber keeps growing. You have a flare gun with you down there, right? In case we need to send a search- oh, yeah." Steve was really going to town down there. Tony could only get a glimpse of him now and then when he repositioned, but his hair rubbed against the underside of his enormous gut as he took Tony's dick into his mouth and hummed. The stubble on his chin rasped erotically against Tony's balls. But the sensations weren't enough to distract Tony from the next two contractions and expansions his body made. He studied his plumped hands that were now like inflated flesh-toned rubber gloves. And then his ass bubbled out more, visibly lifting his hips farther from the surface of the bed.

  
"Too big! Too big! Fucking stop it, Steve! I am not having a fun time right now!"

  
Steve pulled himself put from under the overhang of Tony's belly. He moved up to curl around Tony's head to stroke his hair. "You're okay. You'll be fine. We will be able to fix this, no problem."

  
Tony wiped tears and sweat off of his puffed-up face and replied, "Get your star-spangled erection away from my face, Rogers. I need some consolation; not your dick reaming its way into my ear canal."

  
Steve got a stunned look on his face. "You're really upset about this."

  
"What fucking clued you in?!" Tony snapped. He took a couple deep breaths to calm himself. "Sorry. I'm just afraid I'm going to be a Veruca Salt blueberry boy for the rest of my life. I never thought I would ever beg you to not get handsy with me, but I'm feeling like the fattest girl at the prom, here."

  
"You know I like you for more than your body, right?" Steve's look of discomfort was beginning to edge across the border into panic at having to talk about feelings.

  
"No, Steve," Tony said sarcastically. "You've only been pity-fucking me for nearly eight months. I'm just your side bitch while you are really dating Alyssa Milano."

  
Steve grinned mischievously. "She was nice. I met her at Fashion Week."

  
"When did you go to Fashion Week?"

  
"JARVIS said you were working on upgrading the quinjets' afterburners. Anyway, I might prefer you like this. I would always know where you were, and that you were staying safe."

  
"I would go insane. I don't think these fat hands could handle the torque needed to unscrew a light bulb. I would have to tell that Air Force kid how to maintain Rhodey's suit. Marc, right? Who the fuck spells Mark with a 'c'? JARVIS, patch me through to Bruce. Bruce, if this doesn't get fixed, I will have no choice but to focus all of my awesome brainpower on uploading my consciousness, and the singularity will happen in less than a year. _Less than a year_ , Bruce, then it's Skynet! And Clint will be killed first. Then I will upload you into the Wienermobile. It will be like Knight Rider, but instead of being K.I.T.T. you will be S.H.I.T. And I will recruit Hasselhoff to ride you. Is that what you want, Bruce? David Hasselhoff riding your big wiener? _Forever?_ "

  
"That does sound like a dream come true, Tony," Bruce tried to deadpan in response before cutting the connection, but his snickers were audible.

  
"He doesn't sound worried at all," Steve consoled Tony, with a smile. "See? He will able to undo this easily. Meanwhile, can I ride your big wiener?"

  
Tony huffed and threw his hands up before letting them drop back onto the bed. "If you can find it and if it's in any condition to be ridden, then knock yourself out, cowboy."

  
Steve straddled Tony's hips and sat on his thick thighs. "Hmm," he murmured. "Looks like it needs encouragement." He sprawled over the big mound of Tony's new gut and worked his hand under to start working Tony's cock. "I like feeling smaller. It's turning me on. I never would have thought that would be a thing, since I hated being such a small guy before the serum."

  
Tony spoke out grudgingly. "Seen the photos. You were adorable."

  
"Mmm," Steve hummed, rocking his dick into Tony's flesh. "Would you like me if I was still a brassy little runt? Would you still fuck me if I was short and skinny and needed to rely on a big guy like you to take care of me?"

  
"I take care of you now. You still refuse to use the microwave." Steve's words were having an effect, but Tony was unwilling to give in yet.

  
"Your dick would be thicker than my wrist," Steve added as he sat up and reached for a bottle of lube. He squeezed some onto his fingers and reached back to work himself open. Tony's eyes were locked on the flexing of his shoulders and biceps. "It would take hours to get my ass ready for your cock. The whole time I would be trying to fight you off, but you could hold me down with one hand. I would cuss at you, but we would both still know how much I wanted it."

  
Tony was picturing the scenario Steve was painting with his words. A cute, tiny, little Steve scowling up at him from under his floppy blond hair. Putting up such a show of fighting him, but his adorable leaking dick telling them both the truth. Throwing those stick-thin legs over his shoulders so he could fuck into that delicate, lithe little body. He was gasping now, with his eyes closed. Steve- the real Steve, big Steve, admired how the big flabby breasts on Tony's chest jiggled with his rapid breaths. He used some more lube and began to grease Tony's cock.

  
"I wouldn't scream for help. I wouldn't dare. All I could do was tell you you were a perverted fucking bastard, and beg you get off of me. I'd get tired of fighting back. You'd push your cock into me, and I would bite my lip to keep myself from moaning at how good you felt. You'd be so big, the pressure of it would make tears come out of my eyes. You would laugh, and lick them off my face, and tell me how I was such a slut for you-"

  
Steve pushed himself down onto and around Tony's dick. Both of them groaned at the feeling. "Keep talking, baby," Tony said, fisting his hands in the sheets.

  
Steve caught his breath and grinned ferally at him. "After a few thrusts, I would start begging for you to jerk me. You wouldn't, at first, telling me that fairy whores don't need their dicks to get off; that your cock was good enough to get us both off. But you would eventually wrap your hand around me-"

  
"-Your adorable little dick," Tony cut in, and Steve kept moving his hips to make him slide slow and deep.

  
"My small, skinny dick. Your hand would wrap around it so easy, cover it all up. I could feel your callouses rubbing roughly against my tender skin, and it would hurt a little in the best way. Your thumb, with grease from whatever machine you'd been working on under the nail, would tease the head." Steve pulled Tony's left hand up around his cock and encouraged him to jack him as he kept riding Tony's dick.

"Would you cry when you came?"

  
"I would _scream_ when I came. I'd shoot the biggest load of my life. I would be fucking away from your hand and onto your cock then away from your cock into your hand, trying to escape the flood of sensation. I would fucking _convulse_ when I came, your body holding me down by my hips. I would scream, then cry at the shame of enjoying being fucked by a man. You would ram into me harder after that, shoving my knees up almost all the way to my ears. Bending me in half."

  
"Oh, God," Tony groaned as he reached his peak.

  
"Fuck. Yeah." Steve's gyrations stilled abruptly as he clutched Tony's hand to the head of his dick and spat out come.

  
Their fast, heavy breathing alternated in synchronization; their panting making an audible bitonal rhythm like a heartbeat or the hooves of a galloping horse.

  
JARVIS' voice cut into their afterglow. "Doctor Banner says that he has an antidote waiting for you down in his lab."

  
"See? You're fine," Steve said, pushing Tony's hair off of his sweaty forehead and giving him a kiss.

  
Tony rolled his eyes, but did feel a metaphorical weight lift from his shoulders. "Can he come up here, J?"

  
A second later JARVIS responded, "No, sir. He says the cure must be administered in a controlled environment."

  
"Great!" Steve rolled off of Tony and started putting his clothes on.

  
"Not great. That means I have to haul my fat everything over to the elevator naked. I don't have anything that is close to whale sized."

  
Steve did not allow Tony's facts to dim his enthusiasm. He grabbed Tony by the wrists and hauled him up into a sitting position. "The sooner we leave, the sooner you will be back to normal."

  
Tony twisted to dangle his feet off the side of the bed. It requires both men's efforts to haul him to a standing position.  
"I look like a swarthy Michelin Man! I've got _rolls_ , Steve! Everything is all gross and saggy except for this beach ball of a stomach! How the hell is this possible?!" Tears dropped down from the rosy apples of his round cheeks onto his man-jugs and bloated belly.

  
"It is weird," Steve concurred, looking him over appraisingly. "It looks more like you're pregnant than obese." He dropped to his knees and nuzzled his nose and mouth into Tony's belly bulge. "If you were pregnant right now, it would be mine." He cradled the underside of the fleshy mound as he licked and kissed the oddly firm pudge.

  
"Seriously?! Another kink?! I am missing the days of simple in-and-out missionary-style fucking. I'm started to think that you would really prefer me to be a lardball forever!"

  
"Of course not," Steve denied, looking up over the immensity of Tony's misshapen body. "You wouldn't be happy, or healthy, or able to do a lot of stuff we like to do together. But I wouldn't say no to having a little more time to enjoy this."

  
"Hell's Bells, Steve," Tony said with a sigh. "JARVIS: Bruce. Captain Hard-on wants to go again. Another half hour before taking the antidote won't hurt, right?"

  
"Fine. Just don't tell me any more!" Bruce's strained voice was relayed to them in surround sound.

  
"You are just shoveling me piles of dirt on yourself, Rogers. Okay. I think the internets call it mpreg. Breeding kink? I think Pepper scarred me for life reading me snippets of badly written alien Power Rangers fanfiction; I never thought I would need that knowledge ever in my real life. What do you want me to do?"

  
"Can you bend over the bed? Here, lemme put the pillows under you." Steve practically tripped over his own dick rushing to help Tony get into breeding position.

  
"I almost don't need any pillows," Tony groused. With three pillows propped on the edge of the bed and wedged under his corpulent gut, he was bent over relatively comfortably with his arms bracing his shoulders and head. "Well, this is your show. Talk me into it, you depraved fiend."

  
"There's a name for it? Gee, I had never even considered you being knocked up before you grew this." Steve plastered himself over Tony's back and rubbed his stomach.

  
"There's a name for everything on the web. I'll have JARVIS help you filter through porn sites. Or, ask Clint. I saw him watching some pony girls on his phone the other day during lunch."

  
Steve's hands had moved down to Tony's ass, and his fingers were prodding at the cleft. "I would lick you open, but I don't think my face would fit down there."

  
"Just grab the lube and get started. And you either want to shut me up or start back up with that surprisingly effective sexy-talk. We found your new superpower: a silver tongue in a dirty mouth that rallies reluctant... rods? I can't think of any appropriate R-words. Alliteration fail."

  
"Your body feels empty," Steve began, with the scarcely audible sound of squelching as he oiled his fingers. "You haven't found meaning in your life. Haven't found your purpose yet."

  
"Surprisingly on-target if you were describing me before the Iron Man suit."

  
A wet finger wiggled into the flesh canyon between Tony's mountainous ass cheeks and started stroking over his hole. "You see me, you smell me, you touch me, and your knees go weak, because suddenly your purpose becomes clear to you."

  
"To bend over for your spectacular dick?" Tony mutters.  
Steve twists around him so he can whisper the next words directly into Tony's ear in a rush of humid heat. "You. Are. My. **Bitch.** "

  
Tony swallows hard. "Boi-oi-oing. Bingo."

  
"Suddenly, all you can think about is taking my cock, feeling it pump my virile seed into your cunt. You feel hot with want, the hole between your legs gets needy and wet. Your nipples get hard and start to tingle. Your mouth goes dry. I shove you facedown, just like this, and you spread your thighs and tilt your ass up, arching your back and panting with mindless lust. I fill that emptiness in you with a sharp thrust of my thick cock." Steve did push into him then, thankfully not as forcefully as his words had been implying.

  
" _Hng_ ," Tony groaned. "It does, Steve. You fill me up."

  
"Not yet. I haven't _come_ yet. Tell me how much you want my come in you, baby."

  
Tony swore. "Fuck, Steve, I..." He was at a loss for words, his mouth hung open as Steve's cock impaled him.

  
Steve grabbed Tony's hair in one lube-streaked hand and wrenched his head back. "Tell me how much you want my babies, _slut_."

  
Tony's eyes clenched shut, and his breath sobbed out of him, air being squeezed from his lungs like he was a bellows being worked under Steve's heavy body. "Oh, God. I'm a slut, love it when you call me that. I'm your slut, Steve! Steve!"

  
"What does my slut need?" Steve released his hair with a shove, then smacked the side of Tony's flabby ass cheek with a loud _twhack!_

  
"Ah!" He cried out, startled. " _Your come!_ I need your come! Come in me, fill up my dirty hole. Fill me up, knock me up! Get me big with your babies, make me huge!"

  
"Your tits will be filled with milk. I will handcuff you to the bed; they will grow heavy and hurt, and you won't get any relief until I come in here and milk you like a cow. Even when you've had the baby, I will keep you here. Hook you up to a milking machine when I go away and leave you for days. Hire two nannies: one to take care of our baby, and one to take care of you while you are kept tied up in our bed. Have her change your diapers and feed you your own milk back to you in bottles."

  
Tony wasn't an enthusiastic passenger on this new track Steve's train of filth was taking them, but the guy seemed so into it, pounding into him hard enough to shake the entire bed and rattle the boringly prosaic shaded table lamp Steve insisted he keep on his nightstand. Steve's firm, muscular thighs slapped up against his horrifyingly fat ass and thighs. His hanging chins and boobs were jiggling and mashing into the pillows and bedsheets. Snapped out of erotic humiliation, Tony felt like he was just riding out a storm until Steve finally groaned into his skin and shuddered, panting.

  
It took Steve almost two minutes for his breathing to even out and to regain his composure enough to stand and help Tony straighten up.

  
"Sorry," Steve said, abashed. "I lost you there at the end, didn't I?"

  
"Hey, no kink shaming," Tony protested. "Your fantasies about me can be whatever you want them to be, as long as you still respect my limits when it comes to acting things out."

  
"Let me clean us up, then we can go down and get you back to normal."

  
They had to rig a toga for Tony's massive body out of one of the sheets, and then he had to do the worst walk of shame in his life in his own home. Clint was waiting in a doorway to get an eyeful, but Steve's glare (and possibly threatening gestures, Tony was keeping his burning face turned firmly away from all spectators) prevented anything but a sputter of delighted disgust to be heard from him.

  
If Natasha was watching, there was no sign her. Of course, she could be using JARVIS' own cameras to watch, but Tony really had no clue whether she had any interest or shaudenfreude for his humiliation.

  
He did fit in the elevator, but Steve had to take the stairway due to the weight limit, and meet him further down the hallway.

  
Bruce, thankfully, kept a straight face and professional demeanor. He held up a breaker of slightly blue fluid and told Tony to drink it. After that, there were two more.

  
"This is a lot. I have to drink all of it?" Tony said.

  
"You need to ingest enough amphipathic macromolecules to bind to the psuedolipids and flush them from your body. I expect that you will need to drink more over the next several days to remove the amount of mass you gained."

  
"Fuck me," Tony moaned. "This is a worse drinking-related problem than alcoholism."

  
Bruce gave him a stern glare. "If I had the opportunity to merely drink buckets of shit to permanently shrink down from Hulk size, I would do it in a heartbeat."

  
"You win. Sorry."

  
"Plus, you're my new volunteer for any potentially body-altering experimental compounds."

  
"Wait, you have other shit like this that you're working on?" Tony said, pausing in the forced guzzling of the antidote.  
Bruce eyed Steve through the open lab door, who was on his phone down the hall. "No. But I think it might be amusing to see what other kinks your boyfriend has. If you're up for it."

  
Tony looked at Steve consideringly. "As long as there's a cure, I might be."

**Author's Note:**

> Self-gratification porn that I figured I would share. Hopefully Tony's banter was in character. Thanks for reading; comments and critiques welcome.


End file.
